#include <cstdio>

const int MAX_SIZE(100000);

int v [MAX_SIZE];
int n, k;
long long sum;

inline void read (void)
{
	std::freopen("grupuri.in","r",stdin);
	std::scanf("%d%d",&k,&n);
	for (int *iterator(v), *end(v + n) ; iterator < end ; ++iterator)
	{
		std::scanf("%d",iterator);
		sum += *iterator;
	}
	std::fclose(stdin);
}

inline void print (void)
{
	std::freopen("grupuri.out","w",stdout);
	std::printf("%lld\n",sum / k);
	std::fclose(stdout);
}

inline void compute (void)
{
	--n;
	while (sum / k < v[n])
	{
		sum -= v[n];
		--n;
		--k;
	}
}

int main (void)
{
	read();
	compute();
	print();
	return 0;
}